[Mechanism of the Long-lasting Potentiating Effect of Distigmine on Urinary Bladder Motility].

Distigmine bromide (distigmine) is a carbamate cholinesterase (ChE) inhibitor, which is mainly used for the treatment of myasthenia gravis. Distigmine is also used in Japan for the treatment for underactive bladder and glaucoma. The effectiveness of distigmine for underactive bladder treatment has been confirmed by many clinical reports, and this effect is thought to be caused by potentiating urinary bladder smooth muscle contraction due to inhibition of acetylcholine degradation during micturition. However, the pharmacological effects of distigmine on urinary bladder smooth muscle have not been well studied. The most distinctive pharmacological feature of distigmine is that it shows long-lasting effects than other ChE inhibitors; however, few studies have investigated the persistence of the enhancing effect of distigmine on the contractile function of urinary bladder smooth muscle. Moreover, this mechanism remains unclear. In this review, we present our findings on the mechanism of the potentiating effect of distigmine on isolated guinea pig urinary bladder smooth muscle contraction. We also discuss the long-lasting potentiating effect of distigmine on urinary bladder motility and the mechanism of these effects using guinea pig urinary bladder smooth muscle in vivo and in vitro. In addition, we present our investigations on the long-lasting mechanism of distigmine using recombinant human acetylcholinesterase.

Cholinergic Crisis Owing to Distigmine Bromide Complicated by Hyperosmolar Hyperglycemic State.

Distigmine bromide is widely used to treat neurogenic bladder and causes cholinergic crisis, a serious side effect. We herein report about a patient with distigmine bromide-induced cholinergic crisis complicated by a hyperosmolar hyperglycemic state (HHS). On admission, the patient was diagnosed with HHS based on the medical history and laboratory test results. However, she also had bradycardia, miosis, and low plasma cholinesterase activity. We later found that she had received distigmine bromide, which led to a diagnosis of cholinergic crisis. We suggest that the exacerbation of pathology, including HHS, can cause cholinergic crisis in patients receiving distigmine bromide.

Sustainable Effects of Distigmine Bromide on Urinary Bladder Contractile Function.

Distigmine bromide (distigmine) is a reversible carbamate cholinesterase (ChE) inhibitor that is used to treat myasthenia gravis. In Japan, it is also used as a remedy for urination disorder (underactive bladder). The most distinctive pharmacological feature of distigmine is its long-lasting action compared to that of other ChE inhibitors. In animals and humans, distigmine was reported to inhibit acetylcholinesterase (AChE) and improve myasthenia gravis for an extended period. Few studies have examined the sustainability of this enhancing effect on the contractile function of urinary bladder smooth muscle. In addition, the cause of this long-lasting feature remains unclear. In this review, we present our findings for the long-lasting feature of distigmine on isolated urinary bladder contraction and in vivo urinary function of guinea pig. We also present our results on the mechanism of its long-lasting sustainability using recombinant human AChE.

Effects of Distigmine on the Mechanical Activity of Urinary Bladder Smooth Muscle.

Distigmine bromide (distigmine) is a reversible carbamate cholinesterase (ChE) inhibitor. Its principle clinical application is in the treatment of myasthenia gravis. Distigmine is also used as a remedy for dysuria and glaucoma. Its effectiveness in the management of dysuria has been demonstrated in several clinical reports. Distigmine may improve (enhance) urinary bladder smooth muscle (UBSM) contraction during micturition by inhibiting acetylcholine (ACh) decomposition. However, the pharmacological effects of distigmine on UBSM have not been adequately studied so far. In this review article, we summarize the reported effects of distigmine on the contractile responses elicited by exogenous and endogenous ACh in isolated UBSM preparations. We also discuss the effects of distigmine on the UBSM basal tone and the contractile response of UBSM to ATP, which is co-released with ACh from parasympathetic nerve terminals.

Cholinergic Crisis Caused by Cholinesterase Inhibitors: a Retrospective Nationwide Database Study.

INTRODUCTION: In contrast to information on the effects of organophosphate, pesticide, or environmental exposures, data on cholinergic crisis caused by pharmaceutical cholinesterase inhibitors are sparse. The present study aimed to describe the characteristics, demographics, and mortality of patients with cholinergic crisis caused by pharmaceutical cholinesterase inhibitors using a nationwide inpatient database in Japan. METHODS: We identified patients diagnosed with cholinergic crisis as a result of taking cholinesterase inhibitor medications in the Japanese Diagnosis Procedure Combination inpatient database from July 2010 to March 2016. We examined the patients' characteristics, treatments, and mortality. RESULTS: A total of 235 patients with cholinergic crisis were identified during the 69-month study period. Forty-eight patients required mechanical ventilation (20.4%), and 15 patients died (6.4%) in hospital. The median lengths of hospital stay and intensive care unit stay were 15 days (interquartile range, 6-42) and 4 days (2-8), respectively. Approximately half of all hospitalized patients required catecholamines, atropine, or mechanical ventilation, while the other half did not require any of these treatments. Patients who required catecholamines, atropine, or mechanical ventilation were more likely to die and had longer hospital stays. CONCLUSIONS: Cholinergic crisis caused by pharmaceutical cholinesterase inhibitors is a rare but potentially life-threatening condition. Patients who require mechanical ventilation and catecholamines or atropine have a poorer prognosis.

Long-Lasting Inhibitory Effects of Distigmine on Recombinant Human Acetylcholinesterase Activity.

To elucidate the mechanism whereby distigmine, an underactive bladder remedy, potentiates urinary bladder contractions long-lastingly, the inhibition of recombinant human acetylcholinesterase (rhAChE) by distigmine was investigated. A centrifugal ultrafiltration device, Nanosep® 10K, was used to separate rhAChE and a bound inhibitor from an unbound inhibitor, reaction substrate, and reaction product. This allowed the same aliquot of rhAChE to be repeatedly assayed for up to 48 h to confirm the long-lasting binding of an inhibitor. Cholinesterase (ChE) inhibitors, distigmine, pyridostigmine, neostigmine, and ambenonium, were tested. The dissociation rate constant (kdiss) and dissociation half-life (t1/2) of each inhibitor were determined based on the changes in rhAChE activity. Within 2-4 h after removing pyridostigmine, neostigmine, or ambenonium, the rhAChE activity was restored to the control levels. The kdiss values for pyridostigmine, neostigmine, and ambenonium were calculated to be 0.51±0.05, 0.66±0.03, and 1.41±0.08 h-1, and the t1/2 values were calculated to be 1.36, 1.05, and 0.49 h, respectively. With distigmine, the rhAChE activity initially dropped to 17% of that in the control and then slowly recovered to only 50% by 48 h after drug removal. The kdiss and t1/2 values of distigmine were calculated to be 0.012±0.001 h-1 and 57.8 h, respectively. Based on the t1/2 values, distigmine was judged to dissociate from acetylcholinesterase (AChE) 40-120-fold slower than the other ChE inhibitors did. This may explain the long-lasting potentiation of urinary bladder contractions and motility by distigmine as a treatment for an underactive bladder.

Distigmine Bromide Produces Sustained Potentiation of Guinea-Pig Urinary Bladder Motility by Inhibiting Cholinesterase Activity.

Distigmine is a cholinesterase (ChE) inhibitor used for the treatment of detrusor underactivity in Japan. Distigmine's pharmacological effects are known to be long-lasting, but the duration of its effect on urinary bladder contractile function has not been fully elucidated. The present study aimed to determine these effects in relation to the plasma concentrations of distigmine and its inhibition of ChE activities in blood, plasma, and bladder tissue. Intravesical pressures were recorded in anesthetized guinea-pigs for 12 h after the intravenous administration of saline or distigmine (0.01-0.1 mg/kg). Plasma distigmine concentrations were measured by liquid chromatograph-tandem mass spectrometry (LC-MS/MS), while ChE activities were assayed using 5,5'-dithiobis(2-nitrobenzoic acid). Distigmine (0.1 mg/kg) significantly increased the maximum intravesical pressure at micturition reflex for 12 h post-administration. In contrast, plasma distigmine was only detectable for 6 h post-administration in these animals and a one-compartment model calculated an elimination half-life of 0.7 h. However, bladder and blood acetylcholinesterase activities were significantly inhibited for 12 h after distigmine administration, although plasma ChE activities were not affected. The pharmacodynamic effects of distigmine thus persisted after its elimination from the circulation, indicating that it may bind to bladder acetylcholinesterase, producing sustained enzyme inhibition and enhancement of bladder contractility.

Effect of distigmine on the contractile response of guinea pig urinary bladder to electrical field stimulation.

Distigmine bromide (distigmine) is a reversible carbamate group cholinesterase (ChE) inhibitor. Although mainly used clinically for the treatment of myasthenia gravis, distigmine is also indicated for detrusor underactivity in Japan. According to the pharmacological classification of distigmine, its therapeutic effect against detrusor underactivity appears to be produced by enhanced urinary bladder smooth muscle (UBSM) contractility due to an increased concentration of acetylcholine between parasympathetic nerve endings and UBSM cells. However, ATP as well as acetylcholine is also released from parasympathetic nerve endings that dominate UBSM. The present study was thus carried out to investigate the potentiating effects of distigmine on the two UBSM contractile components in response to parasympathetic nerve stimulation induced by electrical field stimulation (EFS). In isolated guinea pig UBSM tissues, EFS (1-16Hz) produced tetrodotoxin-sensitive, frequency-dependent contractions. The contractile responses to EFS were largely diminished by atropine (10-6M), and the remaining contractile components in the presence of atropine were virtually abolished by α,ß-methylene adenosine triphosphate (α,ß-mATP) (10-4M). Distigmine (10-6M) significantly potentiated EFS-induced contractile components generated in the presence of α,ß-mATP (10-4M), but did not potentiate EFS-induced contractile components generated in the presence of atropine (10-6M). These findings clearly indicate that distigmine strongly potentiates UBSM contraction selectively induced by parasympathetic nerve-derived acetylcholine, suggesting a potential mechanism by which distigmine restores detrusor underactivity.

Spectrophotometric Determination of Distigmine Bromide, Cyclopentolate HCl, Diaveridine HCl and Tetrahydrozoline HCl via Charge Transfer Complex Formation with TCNQ and TCNE Reagents.

The purpose of this investigation was directed to propose sensitive, accurate and reproducible methods of analysis that can be applied to determine distigmine bromide (DTB), cyclopentolate hydrochloride (CPHC), diaveridine hydrochloride (DVHC) and tetrahydrozoline hydrochloride (THHC) drugs in pure form and pharmaceutical preparations via charge-transfer complex formation with 7,7,8,8-tetracyanoquinodimethane (TCNQ) and tetracyanoethylene (TCNE) reagents. Spectrophotometric method involve the addition a known excess of TCNQ or TCNE reagents to DTB, CPHC, DVHC and THHC drugs in acetonitrile, followed by the measurement of the absorbance of the CT complexes at the selected wavelength. The reaction stoichiometry is found to be 1:1 [drug]: [TCNQ or TCNE]. The absorbance is found to increase linearly with concentration of the drugs under investigation which is corroborated by the correlation coefficients of 0.9954-0.9981. The system obeys Beer's law for 6-400, 20-500, 1-180 and 60-560 µg mL(-1) and 80-600, 10-300, 1-60 and 80-640 µg mL(-1) for DTB, CPHC, DVHC and THHC drugs using TCNQ and TCNE reagents, respectively. The apparent molar absorptivity, sandell sensitivity, the limits of detection and quantification are also reported for the spectrophotometric method. Intra- and inter-day precision and accuracy of the method were evaluated as per ICH guidelines. The method was successfully applied to the assay of DTB, CPHC, DVHC and THHC drugs in formulations and the results were compared with those of a reference method by applying Student's t and F-tests. No interference was observed from common pharmaceutical excipients.

A pilot study of acotiamide hydrochloride hydrate in patients with detrusor underactivity.

AIM: To investigate the clinical efficacy of acotiamide hydrochloride hydrate in patients with detrusor underactivity. METHODS: We measured the post-void residual urinary volume in 19 patients with underactive bladders. All these patients had been under treatment with distigmine bromide and were prescribed acotiamide hydrochloride hydrate at a dose of 100 mg three times daily for 2 weeks. RESULTS: Compared with the post-void residual urinary volume value at baseline (161.4±90.0 mL) a statistically significant reduction was observed at the end of treatment (116.3±63.1 mL) (P=0.006). The drug was generally well tolerated by the majority of patients. CONCLUSION: Maybe, acotiamide hydrochloride hydrate showed clinical efficacy in patients with underactive bladders and may, therefore, be used alternatively in patients who do not respond sufficiently to distigmine bromide.